﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Drawing;

namespace SYH.Utils
{
  public   class CheckCodeHelper
    {
        /// <summary>
        /// 生成随机码
        /// </summary>
        /// <param name="codeCount"></param>
        /// <returns></returns>
        public static string RandomCode(int codeCount)
        {
            string allChar = "0,1,2,3,4,5,6,7,8,9";

            string[] allCharArray = allChar.Split(',');
            string randomCode = "";


            for (int i = 1; i <= codeCount; i++)
            {
                Random rand = new Random(i * ((int)DateTime.Now.Ticks));
                var t = rand.Next(9);

                randomCode += allCharArray[t];
            }
            return randomCode;
        }

        /// <summary>
        /// 生成随机码
        /// </summary>
        /// <param name="codeCount"></param>
        /// <returns></returns>
        public  string CreateRandomCode(int codeCount)
        {
            string allChar = "0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,W,X,Y,Z";

            string[] allCharArray = allChar.Split(',');
            string randomCode = "";


            for (int i = 1; i <= codeCount; i++)
            {
                Random rand = new Random(i * ((int)DateTime.Now.Ticks));
                var t = rand.Next(35);

                randomCode += allCharArray[t];
            }
            return randomCode;
        }

        /// <summary>
        /// 创建验证码图片
        /// </summary>
        /// <param name="checkCode"></param>
        public  byte[] CreateImage(string checkCode)
        {
            System.Drawing.Bitmap image = new System.Drawing.Bitmap((int)Math.Ceiling((checkCode.Length * 12.5)), 22);
            System.Drawing.Graphics g = Graphics.FromImage(image);
            System.IO.MemoryStream ms = new System.IO.MemoryStream();

            try
            {
                Random random = new Random();
                g.Clear(Color.White);
                for (int i = 0; i < 2; i++)
                {
                    int x1 = random.Next(image.Width);
                    int x2 = random.Next(image.Width);
                    int y1 = random.Next(image.Height);
                    int y2 = random.Next(image.Height);
                    g.DrawLine(new Pen(Color.Black), x1, x2, y1, y2);
                }
                Font font = new System.Drawing.Font("Arial", 12, (System.Drawing.FontStyle.Bold));
                System.Drawing.Drawing2D.LinearGradientBrush brush = new System.Drawing.Drawing2D.LinearGradientBrush(new Rectangle(0, 0, image.Width, image.Height), Color.Blue, Color.DarkRed, 1.2f, true);
                g.DrawString(checkCode, font, brush, 2, 2);
                for (int i = 0; i < 100; i++)
                {
                    int x = random.Next(image.Width);
                    int y = random.Next(image.Height);
                    image.SetPixel(x, y, Color.FromArgb(random.Next()));
                }
                g.DrawRectangle(new Pen(Color.Silver), 0, 0, image.Width - 1, image.Height - 1);
                image.Save(ms, System.Drawing.Imaging.ImageFormat.Gif);
                brush.Dispose();

                return ms.ToArray();
            }
            catch (Exception ex)
            {
                throw ex;
            }

            finally
            {
                ms.Dispose();
                g.Dispose();
                image.Dispose();
            }
        }
    }
}
